An image pickup apparatus that prevents erroneous recognition of a photographing range when a video acquired using an anamorphic lens is displayed. A system controller determines a type of a lens mounted on a lens mounting section. When the type of the mounted lens is a first lens for scaling a video by a factor of 1/a in a horizontal direction, first aspect markers indicating an aspect ratio of M:N are displayed in a state superimposed on a first video acquired via the first lens. When the type of the mounted lens is a second lens for scaling the video by a factor of 1/b in the horizontal direction, second aspect markers indicating an aspect ratio of M′:N (M′=M×a/b) are displayed in a state superimposed on a second video acquired via the second lens.